.postcss-prefix {
    width: 100px;
    height: 40px;
    background-color: aquamarine;
    /* 和left:0与top:0;的效果相同 */
    inset: 0;
}

/* 2、自定义选择器 */
@custom-selector :--title h1,h2,h3;
@custom-media --media-phone (width<=768px);
@custom-media --sm (width>=640px);
@custom-media --md (width>=768px);
@custom-media --lg (width>=1025px);
@custom-media --xl (width>=1280px);
@custom-media --2xl (width>=1440px);

:--title {
    color: blue;
    @media (--sm) {
        color: red;
    }
    @media (--md) {
        color: yellow;
    }
    @media (--lg) {
        color: purple;
    }
}

/* 图片控制元素尺寸 */
.postcss-img {
    border: 2px solid orange;
    background-image: resolve('kat.jpeg');
    width: width('kat.jpeg');
    height: height('kat.jpeg');
    display: flex;
    align-items: flex-end;
    justify-content: center;
}